Tunnel intersection supporting structure

Abstract

The utility model relates to the technical field of tunnel construction, and provides a tunnel intersection supporting structure which comprises a door frame and an arch frame, the arch frame is formed by splicing a plurality of arch bars, and a first connecting plate and a second connecting plate are welded to the two ends of each arch bar respectively. One end of each arch bar is in bolted connection with the portal or the first connecting plate of the next assembled arch bar through a second connecting plate and is anchored to the inner wall of the main tunnel through grouting of a third anchor pipe, the other end of each arch bar is anchored to the inner wall of the main tunnel through grouting of a second anchor pipe, and a connecting hole used for positioning and penetrating the second anchor pipe is formed in the first connecting plate. One end of the arch bar is connected with the completed portal or arch bar, the other end of the arch bar is locked in the surrounding rock through cooperation of the first connecting plate and the second anchor pipe, it is guaranteed that the arch frame can form a ring smoothly in the primary support, and the effects of positioning and fixing the follow-up arch bar can be achieved in the installation process. Therefore, the two ends of the arch frame can be supported and do not fall off. The intersection construction time is saved, and the construction period is shortened.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction technology, and more specifically, to a support structure for a tunnel intersection. Background Technology

[0002] In mountainous tunnel construction, tunnel entrances located on steep cliffs are becoming increasingly common. When a main tunnel approach is not feasible, auxiliary passages such as working adits or inclined shafts are typically used for construction. Construction at the intersection of the working adit and the main tunnel is a critical challenge. In conventional adit-to-main tunnel construction, lateral excavation at the intersection affects the stability of the surrounding rock, and the newly added support structure is difficult to fix and requires significant material, leading to high resource consumption. Furthermore, low efficiency and long working hours increase safety risks for on-site workers. Utility Model Content

[0003] The purpose of this utility model is to provide a support structure for tunnel intersections, which solves the problems of difficult fixing of support structures, large material consumption, low efficiency and long operation time in the construction of conventional branch tunnels to main tunnels.

[0004] This utility model is achieved through the following technical solution: a tunnel intersection support structure, including a gantry frame anchored at the intersection of the adit and the main tunnel, the gantry frame being connected to an arch frame for the support of the main tunnel, the arch frame being assembled from several arch rods, with a first connecting plate and a second connecting plate welded to both ends of the arch rods respectively, one end of the arch rod being bolted to the gantry frame or the first connecting plate of the next assembled arch rod through the second connecting plate, and being anchored to the inner wall of the main tunnel by grouting through a third anchor pipe, the other end of the arch rod being anchored to the inner wall of the main tunnel by grouting through a second anchor pipe, and a connecting hole for positioning and inserting the second anchor pipe is provided on the first connecting plate.

[0005] Furthermore, the gantry includes uprights, arc rods, and longitudinal support beams. The uprights are respectively attached to both sides of the branch opening, the arc rods are fitted with the outline of the main opening, one end of the longitudinal support beam is connected to the upright, and the other end of the longitudinal support beam is connected to the arc rod. A support beam for supporting the branch opening is provided between the tops of adjacent longitudinal support beams, and a transverse support beam for connecting the arch rod is provided between the ends of adjacent arc rods.

[0006] Preferably, the upper and lower sides of both ends of the arc rod are respectively grouted to anchor the first anchor pipe.

[0007] Preferably, the first anchor pipe is welded to the arc rod on both sides by L-shaped threaded steel, and the second and third anchor pipes are also welded to the arch rod on both sides by L-shaped threaded steel.

[0008] Furthermore, the angle between the axis of the second and third anchor pipes and the tangent of the main tunnel outline is 10° to 30°.

[0009] Furthermore, the second anchor pipes are respectively set on the left and right sides of the front end of the arch rod in the excavation direction, and the third anchor pipes are respectively set on the left and right sides of the rear end of the arch rod in the excavation direction.

[0010] Furthermore, the joints between the arch members and between the arch members and the portal frame are covered with protective sleeves.

[0011] This utility model has at least the following advantages and beneficial effects: By assembling the arch frame in sections, one end of the arch rod is connected to the completed portal frame or arch rod, and the other end is locked in the surrounding rock by the cooperation of the first connecting plate and the second anchor pipe. This not only ensures that the arch frame can smoothly form a ring during the initial support, but also plays a role in positioning and fixing the subsequent arch rods during the installation process. This allows both ends of the arch frame to be supported, thus preventing it from falling off. It also saves construction time at intersections and shortens the construction period. Attached Figure Description

[0012] Figure 1 This utility model provides an installation diagram of a tunnel intersection support structure.

[0013] Figure 2 This is a partial structural diagram of the arch frame in a tunnel intersection support structure provided by this utility model.

[0014] Figure 3 This utility model provides a schematic diagram of the connection between arch members in a tunnel intersection support structure.

[0015] Figure 4 This utility model provides a structural schematic diagram of an arch rod in a tunnel intersection support structure.

[0016] Figure 5 The front view of the gantry in the tunnel intersection support structure provided by this utility model.

[0017] Figure 6 A side view of a gantry in a tunnel intersection support structure provided by this utility model.

[0018] Attached reference numerals: 1-Secondary tunnel, 2-Main tunnel, 3-Portal frame, 31-Upright pole, 32-Arch rod, 33-Longitudinal support beam, 34-Support beam, 35-Transverse support beam, 36-First anchor pipe, 4-Arch frame, 40-Arch rod, 41-First connecting plate, 410-Connecting hole, 42-Second connecting plate, 43-Second anchor pipe, 44-Third anchor pipe. Detailed Implementation

[0019] The specific implementation method is described below with reference to the accompanying drawings.

[0020] Example

[0021] like Figure 1-6As shown in this embodiment, a tunnel intersection support structure is disclosed, which is applicable to the initial support arch frame 4 construction at weak surrounding rock intersections such as tunnel adit 1 turning into main tunnel 2, inclined shaft turning into main tunnel 2, and cross passage turning into main tunnel 2. It includes a gantry 3 anchored at the intersection of adit 1 and main tunnel 2. The gantry 3 is connected to the arch frame 4 for supporting main tunnel 2. The arch frame 4 is assembled from several arch rods 40. The two ends of the arch rods 40 are respectively welded with a first connecting plate 41 and a second connecting plate 42. One end of the arch rod 40 is bolted to the gantry 3 or the first connecting plate 41 of the next assembled arch rod 40 through the second connecting plate 42, and is grouted and anchored to the inner wall of main tunnel 2 through a third anchor pipe 44. The other end of the arch rod 40 is grouted and anchored to the inner wall of main tunnel 2 through a second anchor pipe 43. The first connecting plate 41 is provided with a connecting hole 410 for positioning and inserting the second anchor pipe 43. Specifically, in this embodiment, the first connecting plate 41 is a steel plate of 460mm×200mm×16mm, and the second connecting plate 42 is a steel plate of 260mm×200mm×16mm. The first connecting plate 41 is located at the end of the arch rod 40 away from the branch hole 1, and the second connecting plate 42 is located at the end of the arch rod 40 close to the branch hole 1. Bolt holes for connecting and inserting bolts are opened at corresponding positions on the first connecting plate 41 and the second connecting plate 42. The connecting hole 410 can be a strip hole, and its position should avoid overlapping and interference with the second connecting plate 42 when the arch rod 40 is spliced, ensuring the smooth installation of the second anchor rod, providing a suitable construction angle and limiting method, making construction more convenient, and achieving a better locking effect. It should be noted that the installation position of the second anchor pipe 43 at the front end of the arch rod 40 and the installation position of the third anchor pipe 44 at the rear end of the next arch rod 40 are misaligned along the width direction of the arch rod 40. By assembling the arch frame 4 in sections, early support after excavation was ensured while reducing the waste of additional materials and saving construction time. Compared with the scaffolding method, there is no need to remove excess columns, repair the initial surface, or install the main tunnel arch frame 4, which greatly saves construction time at the intersection and shortens the construction period.

[0022] Furthermore, in a specific implementation, the gantry 3 provided in this embodiment of the present invention includes uprights 31, arc rods 32, and longitudinal support beams 33. The uprights 31 are respectively attached to both sides of the branch hole 1, the arc rods 32 are fitted to the outline of the main hole 2, one end of the longitudinal support beam 33 is connected to the uprights 31, and the other end of the longitudinal support beam 33 is connected to the arc rods 32. A support beam 34 for supporting the branch hole 1 is provided between the tops of adjacent longitudinal support beams 33, and a transverse support beam 35 for connecting the arch rods 40 is provided between the ends of adjacent arc rods 32. Preferably, the upper and lower sides of both ends of the arc rods 32 are respectively grouted and anchored with first anchor pipes 36. Specifically, the first anchor pipe 36 is lapped and welded to the arc rods 32 on both sides by L-shaped threaded steel, and the second anchor pipe 43 and the third anchor pipe 44 are both lapped and welded to the arch rods 40 on both sides by L-shaped threaded steel. During construction, it is difficult to keep the surfaces of the first anchor pipe 36 and the arc rod 32, the second anchor pipe 43 and the third anchor pipe 44 completely perpendicular to the surface of the arch frame 4. This makes it difficult for the pre-processed L-shaped threaded steel bars to simultaneously adhere to the connection surfaces. The bending angle of the L-shaped threaded steel bars is adjusted according to the angle of the connection surfaces on site to ensure that the connection surfaces are tightly attached and to avoid wide-gap welding.

[0023] Furthermore, in specific implementations, the angle between the axes of the second anchor pipe 43 and the third anchor pipe 44 provided in this embodiment of the present invention and the tangent of the outline of the main tunnel 2 is 10° to 30°. This ensures that the second anchor pipe 43 and the third anchor pipe 44 are initially embedded in the surrounding rock without damaging the surrounding rock.

[0024] Furthermore, in specific implementation, the second anchor pipe 43 provided in this utility model embodiment is respectively disposed on the left and right sides of the front end of the arch rod 40 in the digging direction, and the third anchor pipe 44 is respectively disposed on the left and right sides of the rear end of the arch rod 40 in the digging direction.

[0025] Furthermore, in specific implementation, the joint protective sleeves are wrapped around the connections between the arch rods 40 and between the arch rods 40 and the portal frame 3 provided in this utility model embodiment. It should be noted that shotcrete construction can easily cover the joints between the arch rods 40 and between the arch rods 40 and the transverse support beam 35, and the shotcrete on the joint surface is difficult to remove, making it difficult to achieve a tight fit between the arch rods 40. Therefore, before shotcrete construction, easily breakable hard plastic covers are used as joint protective sleeves.

Claims

1. A support structure for a tunnel intersection, characterized in that, The system includes a portal frame (3) anchored at the intersection of the branch tunnel (1) and the main tunnel (2). The portal frame (3) is connected to an arch frame (4) for supporting the main tunnel (2). The arch frame (4) is assembled from several arch rods (40). The two ends of the arch rods (40) are respectively welded with a first connecting plate (41) and a second connecting plate (42). One end of the arch rod (40) is bolted to the portal frame (3) or the first connecting plate (41) of the next assembly of the arch rod (40) through the second connecting plate (42), and is grouted and anchored to the inner wall of the main tunnel (2) through a third anchor pipe (44). The other end of the arch rod (40) is grouted and anchored to the inner wall of the main tunnel (2) through a second anchor pipe (43). The first connecting plate (41) has a connecting hole (410) for positioning and inserting the second anchor pipe (43).

2. The tunnel intersection support structure according to claim 1, characterized in that, The gantry (3) includes uprights (31), arc rods (32), and longitudinal support beams (33). The uprights (31) are respectively attached to both sides of the branch hole (1). The arc rods (32) are fitted to the outline of the main hole (2). One end of the longitudinal support beam (33) is connected to the uprights (31), and the other end of the longitudinal support beam (33) is connected to the arc rods (32). A support beam (34) for supporting the branch hole (1) is provided between the tops of adjacent longitudinal support beams (33), and a transverse support beam (35) for connecting the arch rods (40) is provided between the ends of adjacent arc rods (32).

3. The tunnel intersection support structure according to claim 2, characterized in that, The upper and lower sides of the arc rod (32) are respectively grouted and anchored to form the first anchor pipe (36).

4. A tunnel intersection support structure according to claim 3, characterized in that, The first anchor pipe (36) is welded to the arc rod (32) on both sides by an L-shaped threaded steel bar, and the second anchor pipe (43) and the third anchor pipe (44) are both welded to the arch rod (40) on both sides by an L-shaped threaded steel bar.

5. A tunnel intersection support structure according to claim 1, characterized in that, The angle between the axis of the second anchor pipe (43) and the third anchor pipe (44) and the tangent of the outline of the main hole (2) is 10° to 30°.

6. A tunnel intersection support structure according to claim 1, characterized in that, The second anchor pipe (43) is respectively set on the left and right sides of the front end of the arch rod (40) in the digging direction, and the third anchor pipe (44) is respectively set on the left and right sides of the rear end of the arch rod (40) in the digging direction.

7. A tunnel intersection support structure according to claim 1, characterized in that, The joints between the arch rods (40) and between the arch rods (40) and the gantry (3) are covered with joint protective sleeves.

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